Colchicine induction of Tetraploid Plants from Cultured Bulbscale Discs of the Easter lily Lilium longiflorum Thumb

The demands for genetic improvement of plants are rising and the methods to propagate superior plants are improving through tissue culture. Lilium species are commercially propagated by scaling. The base of each bulbscale initiates a few bulblets. Recently, slices of bulbscales were successfully cultured in vitro and numerous bulblets were directly initiated from the explants, producing an abundance of plantlets. This practice of in vitro vegetative propagation of Lilium species not only increases efficiency of multiplying plantlets but also facilitates induction of polyploidy. Polyploids are frequently demanded for genetic studies and also for their desirable characteristics. Except for the tiger lily, Lilium tigrinum, which is triploid, polyploid strains are not available in nature. It is therefore necessary to obtain them through artificial processes. Since Emsweller and Brierley first induced tetraploidy in Lilium formosanum by exposing the apical meristem of flowering stalk to colchicine solutions, several modifications have been applied in in vivo production of polyploid lilies. Nevertheless, the rate of success was not predictable. Recently Huang induced polyploids in Lilium plants through tissue culture, but the efficiency of his method was not reported. The objective of this research was to evaluate a colchicine treatment method for inducing polyploidy in a bulbscale culture of Lilium longiflorum